The technology of the present disclosure relates generally to distributed antenna systems (DASs) for distributing communications to remote areas each forming a coverage area, and more particularly to optical fiber-based DASs configured to distribute small cell communications from multiple small cell service providers.
A cellular communications system can be provided that includes cellular base stations configured to communicate with cellular client devices to provide cellular communications services. These cellular base stations are typically co-located with cellular antennas configured to distribute transmitted wireless cellular communications signals from a cellular base station to cellular client devices residing within the wireless range of a cellular antenna. The cellular antennas are also configured to receive transmitted wireless cellular communications signals from cellular client devices to the cellular base station for transmission over a cellular network.
It may be desired to distribute cellular communications services remotely, such as in a building or other facility, to provide clients access to such cellular communications services within the building or facility. One approach to distributing cellular communications services in a building or facility involves use of radio frequency (RF) antenna coverage areas, also referred to as “antenna coverage areas.” The antenna coverage areas can have a radius in the range from a few meters up to twenty meters, as an example. Combining a number of access point devices creates an array of antenna coverage areas. Because the antenna coverage areas each cover small areas, there are typically only a few users (clients) per antenna coverage area. This allows for minimizing the amount of RF bandwidth shared among the wireless system users.
As an example, FIG. 1 illustrates distribution of cellular communications services to remote coverage areas 10 of a DAS 12. In this regard, the remote coverage areas 10 are created by and centered on remote antenna units 14 connected to a head-end equipment 16 (e.g., a head-end controller or head-end unit). The head-end equipment 16 is communicatively coupled to a cellular base station (not shown). The remote antenna units 14 receive cellular communications services from the head-end equipment 16 over a communications medium 18 to be distributed in their coverage area 10. Each remote antenna unit 14 may also include an RF transmitter/receiver and an antenna 20 operably connected to the RF transmitter/receiver to wirelessly distribute the cellular communication services to cellular client devices 22 within the coverage area 10. The size of a given coverage area 10 is determined by the amount of RF power transmitted by the remote antenna unit 14, the receiver sensitivity, antenna gain and the RF environment, as well as by the RF transmitter/receiver sensitivity of the cellular client device 22. Cellular client devices 22 usually have a fixed RF receiver sensitivity, so that the above-mentioned properties of the remote antenna unit 14 mainly determine the size of the remote coverage areas 10.
With ever-increasing demands for high-speed data communication services, it may also be desired to distribute small cell communications within the same building or other facility in which the DAS 12 is deployed. Small cell communications units have a digital backhaul. Small cells may include cellular service small cells, Wireless Fidelity (WiFi) Access Points, 60 GHz radio devices, digital DAS and remote radio heads (RRHs), location radio nodes, wireless readers, and radio nodes for specific applications, like Wireless Medical Telemetry System (WMTS) for example. Fifteen (15) to forty (40) small cells may be required to be deployed in the building for each small cell service. Thus, a building may be first served by a cellular distributed antenna system, like the DAS 12 in FIG. 1, for example. Other equipment and small cells may then be deployed in the building to support other small cell communications services. However, the capacity of the building to support the additional equipment and small cells may be limited.